Summary

Nearly 5 years ago, a large study showed that taking an anti-HIV pill each day can protect people at high risk of becoming infected. But despite several confirmatory trials and approval by the U.S. Food and Drug Administration, so-called pre-exposure prophylaxis, or PrEP, hasn't been used much. New studies reported last week at a major HIV/AIDS conference in Seattle, Washington, promise to make PrEP far more popular. The studies once again show that PrEP offers solid protection for men who have sex with men and heterosexuals—if it is used as prescribed. But they go further and show novel ways to take advantage of PrEP, including "on-demand" usage right before and after having sex. A new model also shows how PrEP can be used to bend the curves of local epidemics.